How long do interconnect cables last? Would anyone use 20 year old cables?

Well. I like the sound of the Cardas Quadlink rca interconnect from source to BHK Preamp so much that I tried Cardas Parsec balanced cables from BHK Pre to M700 monoblocks, and have now had some time in the system and have gone back and forth with Audioquest Red River balanced from BHK Pre to M700. The cardas parsec xlr does sound cleaner and smoother than the red river, but also slightly muffled at the same time, and with less bloom with female vocals. The red river xlr has more bloom and female vocals and violins sound more alive and not muffled, but also not as clean. I am keeping the Audioquest Red River in the system for now. The question I have is how would the sound of the parsec xlr be expected to change and improve over time?